From 4e12e9055cf42574a577248542866caaf2a399d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alberto=20Miedes=20Garc=C3=A9s?= <albertomg994@gmail.com>
Date: Tue, 3 Jan 2017 16:27:11 +0100
Subject: [PATCH] Refactor GraphQL::TypeCreator

---
 lib/graph_ql/type_creator.rb | 49 ++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 19 deletions(-)

diff --git a/lib/graph_ql/type_creator.rb b/lib/graph_ql/type_creator.rb
index aa303ec58..2a4a4ad45 100644
--- a/lib/graph_ql/type_creator.rb
+++ b/lib/graph_ql/type_creator.rb
@@ -24,29 +24,18 @@ module GraphQL
         description("#{model.model_name.human}")
 
         # Make a field for each column, association or method
-        fields.each do |name, type|
-          case GraphQL::TypeCreator.type_kind(type)
+        fields.each do |field_name, field_type|
+          case TypeCreator.type_kind(field_type)
           when :scalar
-            field name, SCALAR_TYPES[type]
+            field(field_name, SCALAR_TYPES[field_type])
           when :simple_association
-            field(name, -> { type_creator.created_types[type] }) do
-              resolve -> (object, arguments, context) do
-                target_public_elements = type.respond_to?(:public_for_api) ? type.public_for_api : type.all
-                wanted_element = object.send(name)
-                if target_public_elements.include?(wanted_element) || GraphQL::TypeCreator.matching_exceptions.include?(name)
-                  wanted_element
-                else
-                  nil
-                end
-              end
+            field(field_name, -> { type_creator.created_types[field_type] }) do
+              resolve TypeCreator.create_association_resolver(field_name, field_type)
             end
           when :paginated_association
-            type = type.first
-            connection(name, -> { type_creator.created_types[type].connection_type }) do
-              resolve -> (object, arguments, context) do
-                target_public_elements = type.respond_to?(:public_for_api) ? type.public_for_api : type.all
-                object.send(name).all & target_public_elements.all
-              end
+            field_type = field_type.first
+            connection(field_name, -> { type_creator.created_types[field_type].connection_type }) do
+              resolve TypeCreator.create_association_resolver(field_name, field_type)
             end
           end
         end
@@ -56,6 +45,28 @@ module GraphQL
       return created_type # GraphQL::ObjectType
     end
 
+    def self.create_association_resolver(field_name, field_type)
+      -> (object, arguments, context) do
+        allowed_elements = target_public_elements(field_type)
+        requested_elements = object.send(field_name)
+        filter_forbidden_elements(requested_elements, allowed_elements, field_name)
+      end
+    end
+
+    def self.target_public_elements(field_type)
+      field_type.respond_to?(:public_for_api) ? field_type.public_for_api : field_type.all
+    end
+
+    def self.filter_forbidden_elements(requested, allowed_elements, field_name=nil)
+      if field_name && matching_exceptions.include?(field_name)
+        requested
+      elsif requested.respond_to?(:each)
+        requested.all & allowed_elements.all
+      else
+        allowed_elements.include?(requested) ? requested : nil
+      end
+    end
+
     def self.type_kind(type)
       if SCALAR_TYPES[type]
         :scalar